Friday, June 10, 2016

Why “Average” Cholesterol Values Can Be So Bad

With all the fuss about cholesterol, how can such a thing happen? Does it mean that cholesterol, LDL in particular, should be even lower to provide protection against heart attack and heart disease?

Not necessarily. What it does mean is that the causes for heart disease should be sought beyond cholesterol.

With Jack, we performed a blood test called lipoprotein analysis using a technique called nuclear magnetic resonance, or NMR. Despite the seemingly complicated name, it is a simple blood test that, in my experience, uncovers hidden causes for heart disease even when standard cholesterol numbers look fine. Jack's lipoprotein panel told an entirely different story. 

In this technique, there is an actual count of the number of LDL particles present in Jack's blood, rather than the calculation usually used to obtain standard LDL cholesterol. Jack's LDL particle number was 1880 nmol/l, a very high value among the worst 10% of men and women. LDL particle number of 1880 nmol/l is approximately the same as LDL cholesterol of 188 mg/dl (simply drop the last digit to generate an approximate "true" LDL), almost 70 mg higher than the estimated value of 119 mg. (This degree of inaccuracy, in fact, is not at all uncommon.)

Lipoprotein analysis also examines the size of LDL particles-large, small, or in-between. 95% of all Jack's LDL particles were small, a very severe pattern. The Quebec Cardiovascular Study is among the clinical studies demonstrating that the combination of high LDL particle number and small LDL raises heart disease risk by 600%. 

Jack also showed a severe excess of intermediate-density lipoprotein (218 nmol/l). This is an important pattern that suggests that dietary fats are not cleared for 24 hours or so after a meal, a phenomenon that heightens risk forcarotid disease and strokeaneurysms, as well as heart disease.